In the resting state the myosin head has ADP and Pi bound. Once the binding site is exposed the myosin head releases Pi and binds to the actin molecule forming a cross-bridge. ADP is released and the head bends pulling the actin towards the middle of the sarcomere. The binding of ATP breaks the cross-bridge and the myosin head detaches. Hydrolysis of ATP returns the myosin head to its resting state. It is then free to bind to another binding site further along.